Two times as many American high school students used e-cigarettes in 2018 compared to the number of high school users last year.
がすっきりとわかりません。
twice as many students as の用法の応用変形でしょうか?
Twice as many students use e-cigarettes compared to last year.
「2倍」は twice as many や two times as many の両方は大丈夫ですね。
質問者が書いた Two times as many American high school students used e-cigarettes in 2018 compared to the number of high school users last year のは、すっきりです。
ネイティブが言う通り文になります。
参考になれば幸いです。
Twice as many students have been vaping compared to last year.
yukoさん
ご質問どうもありがとうございます。
上の文脈を英語で表現するには、下記の言い方ではいかがでしょうか。
- Twice as many students have been vaping compared to last year.
---to vape = 電子タバコする
ご参考にしていただければ幸いです。